During the development of genomic methods it has become evident that they are not able to yield sufficient results for completely describing metabolic pathologies and therefore additional methods from cellular energetics and proteomics have to be applied. Such systematic approach has led to quite surprising results in samples from the tumorous tissue. Otto Warburg was the first to describe high glycolytic rate in malignant cells even under normoxia, however, his hypothesis about this being the main cause of malignancy was discredited with the emergence of new discoveries in following years. In addition to widespread reorganization in the cellular energetics of cancerous cells (e.g. truncated Krebs cycle, respiratory chain supercomplexes), it has been shown that the malignant tissue can make the surrounding stroma to produce metabolites needed by tumour cells. It is believed that an intrinsic understanding of malignancy, as well as of possible drug targets and better treatment strategies can be gained from such systematic approach in tumour biology.